1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
/* Copyright (c) 2000, 2025, Oracle and/or its affiliates.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License, version 2.0,
as published by the Free Software Foundation.
This program is designed to work with certain software (including
but not limited to OpenSSL) that is licensed under separate terms,
as designated in a particular file or component or in included license
documentation. The authors of MySQL hereby grant you an additional
permission to link the program and your derivative works with the
separately licensed software that they have either included with
the program or referenced in the documentation.
Without limiting anything contained in the foregoing, this file,
which is part of C Driver for MySQL (Connector/C), is also subject to the
Universal FOSS Exception, version 1.0, a copy of which can be found at
http://oss.oracle.com/licenses/universal-foss-exception.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License, version 2.0, for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
/**
@file mysys/my_write.cc
*/
#include "my_config.h"
#include <errno.h>
#include <stddef.h>
#include <sys/types.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "my_compiler.h"
#include "my_dbug.h"
#include "my_inttypes.h"
#include "my_io.h"
#include "my_sys.h"
#include "my_thread_local.h"
#include "mysys_err.h"
#if defined(_WIN32)
#include "mysys/mysys_priv.h"
#endif
#include <algorithm>
extern PSI_stage_info stage_waiting_for_disk_space;
#ifndef _WIN32
// Mock away write() for unit testing.
ssize_t (*mock_write)(int fd, const void *buf, size_t count) = nullptr;
#endif
/**
Write a chunk of bytes to a file
if (MyFlags & (MY_NABP | MY_FNABP))
returns
0 if Count == 0
On success, 0
On failure, (size_t)-1 == MY_FILE_ERROR
otherwise
returns
0 if Count == 0
On success, the number of bytes written.
On partial success (if less than Count bytes could be written),
the actual number of bytes written.
On failure, (size_t)-1 == MY_FILE_ERROR
*/
size_t my_write(File Filedes, const uchar *Buffer, size_t Count, myf MyFlags) {
int64_t sum_written = 0;
uint errors = 0;
const size_t initial_count = Count;
size_t ToWriteCount;
DBUG_TRACE;
/* The behavior of write(fd, buf, 0) is not portable */
if (unlikely(!Count)) return 0;
DBUG_EXECUTE_IF("simulate_no_free_space_error",
{ DBUG_SET("+d,simulate_file_write_error"); });
for (;;) {
errno = 0;
ToWriteCount = Count;
DBUG_EXECUTE_IF("force_wait_for_disk_space", { ToWriteCount = 1; });
DBUG_EXECUTE_IF("simulate_io_thd_wait_for_disk_space", {
if (strstr(my_filename(Filedes), "slave-relay-bin.0")) ToWriteCount = 1;
});
DBUG_EXECUTE_IF("simulate_random_io_thd_wait_for_disk_space", {
if (strstr(my_filename(Filedes), "slave-relay-bin.0")) {
if (rand() % 3 == 0)
ToWriteCount = Count;
else
ToWriteCount = std::min(Count, 1 + (Count * (rand() % 100) / 100));
}
});
int64_t writtenbytes =
#ifdef _WIN32
my_win_write(Filedes, Buffer, ToWriteCount);
#else
(mock_write ? mock_write(Filedes, Buffer, ToWriteCount)
: write(Filedes, Buffer, ToWriteCount));
#endif
DBUG_EXECUTE_IF("simulate_file_write_error", {
errno = ENOSPC;
writtenbytes = -1;
});
DBUG_EXECUTE_IF("force_wait_for_disk_space", { errno = ENOSPC; });
DBUG_EXECUTE_IF("simulate_io_thd_wait_for_disk_space", {
if (strstr(my_filename(Filedes), "slave-relay-bin.0")) errno = ENOSPC;
});
DBUG_EXECUTE_IF("simulate_random_io_thd_wait_for_disk_space", {
if (strstr(my_filename(Filedes), "slave-relay-bin.0") &&
ToWriteCount != Count)
errno = ENOSPC;
});
if (writtenbytes == static_cast<int64_t>(Count)) {
sum_written += writtenbytes;
break;
}
if (writtenbytes != -1) { /* Safeguard */
sum_written += writtenbytes;
Buffer += writtenbytes;
Count -= writtenbytes;
}
set_my_errno(errno);
if (is_killed_hook(nullptr))
MyFlags &= ~MY_WAIT_IF_FULL; /* End if aborted by user */
if ((my_errno() == ENOSPC || my_errno() == EDQUOT) &&
(MyFlags & MY_WAIT_IF_FULL)) {
PSI_stage_info old_stage;
if (MyFlags & MY_REPORT_WAITING_IF_FULL) {
set_waiting_for_disk_space_hook(nullptr, true);
enter_stage_hook(nullptr, &stage_waiting_for_disk_space, &old_stage,
__func__, __FILE__, __LINE__);
}
wait_for_free_space(my_filename(Filedes), errors);
if (MyFlags & MY_REPORT_WAITING_IF_FULL) {
enter_stage_hook(nullptr, &old_stage, nullptr, __func__, __FILE__,
__LINE__);
set_waiting_for_disk_space_hook(nullptr, false);
}
errors++;
DBUG_EXECUTE_IF("simulate_no_free_space_error",
{ DBUG_SET("-d,simulate_file_write_error"); });
if (is_killed_hook(nullptr)) break;
continue;
}
if (writtenbytes != 0 && writtenbytes != -1 && !is_killed_hook(nullptr))
continue; /* Retry if something written */
if (my_errno() == EINTR) {
continue; /* Interrupted, retry */
} else if (writtenbytes == 0 && !errors++) /* Retry once */
{
/* We may come here if the file quota is exeeded */
continue;
}
break;
}
if (MyFlags & (MY_NABP | MY_FNABP)) {
if (sum_written == static_cast<int64_t>(initial_count))
return 0; /* Want only errors, not bytes written */
if (MyFlags & (MY_WME | MY_FAE | MY_FNABP)) {
MyOsError(my_errno(), EE_WRITE, MYF(0), my_filename(Filedes));
}
return MY_FILE_ERROR;
}
if (sum_written == 0) return MY_FILE_ERROR;
return sum_written;
}
|
